Thoracic Three-dimensional Spiral CT Findings of an Infant with Spondylothoracic Dysostosis
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《美国医学杂志》
Department of Pediatrics, Division of Allergy and Chest Diseases, Istanbul University, Medical Faculty, Istanbul, Turkey
Abstract
Spondylocostal dysostoses are a group of rare inherited disease with a heterogeneous disorder of vertebral segmentation defects and rib anomalies, which lead to respiratory problems predicting the clinical outcome. Spiral CT with three-dimensional (3D) imaging provides exact measurement of the bony rib cage. We report a case of an infant with spondylothoracic dysostosis, a phenotype of spondylocostal dysostoses, and 3D spiral CT findings of his rib cage since it may contribute to the surgical planning.
Keywords: Infant; Rib cage; Spiral CT
Spondylocostal dysostoses are a group of rare inherited disease with a heterogeneous disorder of vertebral segmentation defects and rib anomalies. Cleft vertebrae, hemivertebrae, butterfly vertebrae, absence of ribs or bifid / fused ribs and short stature due to short trunk are the predominant features.[1]-[3] Respiratory problems are common and prognosis varies considerably but mainly depends on the pulmonary status. Although patients can be lost in early childhood in the presence of severe respiratory distress, they may survive into adulthood with limited symptoms in the milder form.[4]-[5] Reconstructive surgery of the thoracic cage may change the prognosis in children with abnormal chest configuration, which is contradictory.[6]-[7]
The authors report a case of an infant with spondylothoracic dysostosis (STD), a phenotype of SCD, and describe the 3D spiral CT findings of his rib cage. This procedure may help to a better evaluation for surgical intervention.
Case Report
0AA, a boy was born at 34 weeks of gestational age with a birth weight 2010 grams and Apgar scores 4 and 8 as the second child of healthy, non-consanguineous couple. Vertebral anomalies were firstly noticed at the 20th gestational age by ultrasonography during prenatal period but the parents decided not to terminate the pregnancy.
Physical examination revealed mild cyanosis, tachypnea, dyspnea, retractions and rales, asymmetrically malformed thorax and imperforate anus, which was operated on the first day of his life. Chest X-ray demonstrated multiple vertebral deformities, which included fusion of the C6 and C7, L3 and L4, and right pedicular agenesia on L4, vertebral segmentation and fusion anomalies from T4 to T9, butterfly vertebra on T4 and marked costal anomalies. Abdominal, cranial and cardiac ultrasonographic examinations were normal. Blood and urine amino acids by thin layer chromatography were within normal levels. Tethered cord on spinal MRI was surgically corrected at three months of age.
He was readmitted to the hospital when he was one month old because of respiratory failure associated with RSV infection that required mechanical ventilation for five days. At the sixth month visit, physical examination revealed tachypnea, dyspnea, and paradoxical chest wall movements. He had an oxygen saturation of 95% in room air on pulse oxymeter and a pH of 7.347 and pCO2 of 46.8 mm Hg on venous blood sample. Thorax CT scan was performed for better evaluation of the lung parenchyma. Peribronchovascular interstitial thickness was observed in bilateral paracentral zones particularly, in lower lobes Figure1. Spiral thorax CT with 3D reconstruction was performed to show rib cage deformities obviously. Whole rib cage scanned with 3D CT (Hitachi, WSR1050, Japan. Scan parameters were 120 kV, 175 mA with a slice and collimation of 3 mm and a table speed of 5 mm/sec were used). Agenesia of the right 6th and 7th ribs, fusion of the 1st and the 2nd ribs on the left, 3rd and 4th ribs on the right hemithorax and bilateral fusion of the 8th and 9th ribs were detected [Figures 2] and Figure3.
Discussion
Spondylocostal dysostosis (SCD) has been known by various names, including Jarcho-Levin syndrome, hereditary malformations of the vertebral bodies, syndrome of bizarre vertebral anomalies, costovertebral dysplasia.[8] Since the first child with multiple vertebral segmentation defects was described in 1938 by Jarcho and Levin, less than 100 cases have been reported in the literature.[9]
Mortier et al[10] recognized 3 distinct entities based on radiographic and clinical findings: Jarcho-Levin syndrome, a lethal autosomal recessive form, characterised by a symmetric crab-chest; SCD, an autosomal dominant condition with intrinsic rib anomalies and a better prognosis; and STD, which shows considerable clinical and radiographic overlap with the latter type and greater incidence of neural tube defects. But, Cornier et al[9] recently classified clinical phenotypes into two groups: Jarcho-Levin syndrome and STD together constituted one phenotype and spondylocostal dysostosis, the other one. Typical findings of the first phenotype consist of multiple skeletal anomalies including segmentation and formation defects throughout cervical, thoracic and lumbar spine, such as hemivertebrae, block vertebrae, with fusion of the ribs at the costovertebral junction and other accompanying anomalies such as spina bifida, hernias, and imperforate anus. Typical findings of the spondylocostal dysostosis are axial skeletal malformations, but with asymmetric rib anomalies such as broadening, fusion of the ribs and other associated anomalies like congenital cardiac, urogenital diseases, anal atresia. Turnpenny[11] et al reported novel mutations in the Delta-like 3 (DLL3) gene on chromosome 19 in patients with autosomal recessive type spondylocostal dysostosis. Vertebral and costal anomalies detected in our patient and presence of respiratory distress, tethered cord, imperforate anus suggest the possibility of spondylothoracic dysostosis. The chromosomal analysis of the patient was not performed since the parents were reluctant for testing because of their religious believes.
Cornier et al[10] reported that patients with SCD had better prognosis than patients with STD due to asymmetry of the thoracic anomalies resulting in a less restrictive thorax in SCD. It is important to determine the respiratory status in these patients, since it predicts the clinical outcome. Radiographic findings on chest X-ray are difficult to interpret because of the malformed rib cage and not related to the severity of the respiratory problems[5]. CT imaging may be preferred in the evaluation of these children but there are some challenges as rapid respiratory rate, movements, small size and little internal fat to provide intrinsic contrast. Spiral CT is able to address some of these issues because of the speed of data acquisition, which helps to eliminate interscan and intrascan motion resulting in true volume data sets. The short scanning time of spiral acquisition like 32-40 seconds allows the procedure to be performed without sedation in pediatric patients. Spiral CT with 3D imaging provides exact measurement of the bony rib cage.[12]-[14] Cornier et al[10] demonstrated features of rib and vertebral anomalies in patients with STD and SCD with reconstructed 3D spiral CT. We also showed our patient's rib cage abnormalities with the same method.
Paradoxical chest movements, herniation of the lungs and diaphragm through the defect, recurrent respiratory infections lead to progressive thoracic insufficieny in children with spondylocostal dysostoses. Nichter et al[6] did the first chest wall reconstruction in an infant with SCD and reported that they could correct paradoxical chest wall motions of the infant successfully. Hosalkar et al[7] used a latissimus dorsi flap to stabilize the chest wall in a 6 months old infant with SCD recently and declared that the child had improved pulmonary function throughout 8 months after the surgery. Children with the mentioned findings above may benefit from the reconstructive surgery. Our patient's parents have not decided to a reconstructive surgical procedure yet for their child.
Reconstructive 3D spiral CT imaging may help better understanding and visualization of the infant's deformities and status and better evaluation of surgical intervention in children with chest wall anomalies by the family and the surgical team.
References
1. Taybi H. Syndromes. In Taybi H, Lachman RS, eds. Radiology of Syndromes, Metabolic Disorders and Skeletal Dysplasias . 4th edn. St Louis:Mosby, 1996: 466-467.
2. Multiple Congenital Anomalies. In Winter RM, Baraitser M, eds. A Diagnostic Compendum. London: Chapman and Hall Medical, 1991: 583.
3. Kher A, Bhat M, Ratnam KL et al. Spondylocostal dysostosis. Indian J Pediatr 1993; 60: 813-818.
4. Turnpenny PD, Thwaites RJ, Boulos FN. Evidence for variable gene expression in a large inbred kindred with autosomal recessive spondylocostal dysostosis. J Med Genet 1991; 28:27-33.
5. Dorrepaal C, Sonderen L, Hennekam RCM. A neonate with multiple segmentation defects. Pediatric Clinics Amsterdam 1999; 10:2 (http://home-2.worldline.nl/~staalman/PCA/pca10_2/pca10_2_2.html).
6. Nichter LS, Chapin SD, Wells W, Downey SE. Chest-wall reconstruction for sponylocostal dysostosis. Plast Reconstr Surg 1993; 92: 746-749.
7. Hosalkar H, Thatte MR,Yagnik MG. Chest-wall reconstruction in sponylocostal dysostosis. Rare use of latissimus dorsi flap. Plast Reconstr Surg 2002; 110: 537-540.
8. Karakurt C, Kara C, Akgün D et al. Spondylocostal dysostosis: presentation of two cases. Int Pediatr 2001; 16: 173-174.
9. Cornier AS, Ramirez N, Carlo S, Reiss A. Controversies surrounding Jarcho-Levin syndrome. Curr Opin Pediatr 2003; 15: 614-620.
10. Mortier GR, Lachman RS. Multiple vertebral segmentation defects: Analysis of 26 new patients and review of the literature. Am J Med Genet 1996; 61: 310-319.
11. Turnpenny PD, Whittock N, Duncan J et al. Novel mutations in DLL3, a somitogenesis gene encoding a ligand for the Notch signalling pathway, cause a consistent pattern of abnormal vertebral segmentation in spondylocostal dysostosis. J Med Genet 2003; 40: 333-339.
12. Padhani RG, Dixon AK. Whole body computed tomography: recent development. In Grainger AR, Allison DJ, Adam A, Dixon AK, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. Florida: W.B. Saunders Co, 2001: 81-92.
13. Richenberg JL, Hansell DM. Image processing and spiral CT of the thorax. Br J Radiol 1998; 71: 708-716.
14. Pretorius ES, Haller JA. Spiral CT with 3D reconstruction in children requiring for failure of chest wall growth after pectus excavatum surgery. Clin Imaging 1998; 22: 108-116.(Tamay Zeynep, Guler Nermi)
Abstract
Spondylocostal dysostoses are a group of rare inherited disease with a heterogeneous disorder of vertebral segmentation defects and rib anomalies, which lead to respiratory problems predicting the clinical outcome. Spiral CT with three-dimensional (3D) imaging provides exact measurement of the bony rib cage. We report a case of an infant with spondylothoracic dysostosis, a phenotype of spondylocostal dysostoses, and 3D spiral CT findings of his rib cage since it may contribute to the surgical planning.
Keywords: Infant; Rib cage; Spiral CT
Spondylocostal dysostoses are a group of rare inherited disease with a heterogeneous disorder of vertebral segmentation defects and rib anomalies. Cleft vertebrae, hemivertebrae, butterfly vertebrae, absence of ribs or bifid / fused ribs and short stature due to short trunk are the predominant features.[1]-[3] Respiratory problems are common and prognosis varies considerably but mainly depends on the pulmonary status. Although patients can be lost in early childhood in the presence of severe respiratory distress, they may survive into adulthood with limited symptoms in the milder form.[4]-[5] Reconstructive surgery of the thoracic cage may change the prognosis in children with abnormal chest configuration, which is contradictory.[6]-[7]
The authors report a case of an infant with spondylothoracic dysostosis (STD), a phenotype of SCD, and describe the 3D spiral CT findings of his rib cage. This procedure may help to a better evaluation for surgical intervention.
Case Report
0AA, a boy was born at 34 weeks of gestational age with a birth weight 2010 grams and Apgar scores 4 and 8 as the second child of healthy, non-consanguineous couple. Vertebral anomalies were firstly noticed at the 20th gestational age by ultrasonography during prenatal period but the parents decided not to terminate the pregnancy.
Physical examination revealed mild cyanosis, tachypnea, dyspnea, retractions and rales, asymmetrically malformed thorax and imperforate anus, which was operated on the first day of his life. Chest X-ray demonstrated multiple vertebral deformities, which included fusion of the C6 and C7, L3 and L4, and right pedicular agenesia on L4, vertebral segmentation and fusion anomalies from T4 to T9, butterfly vertebra on T4 and marked costal anomalies. Abdominal, cranial and cardiac ultrasonographic examinations were normal. Blood and urine amino acids by thin layer chromatography were within normal levels. Tethered cord on spinal MRI was surgically corrected at three months of age.
He was readmitted to the hospital when he was one month old because of respiratory failure associated with RSV infection that required mechanical ventilation for five days. At the sixth month visit, physical examination revealed tachypnea, dyspnea, and paradoxical chest wall movements. He had an oxygen saturation of 95% in room air on pulse oxymeter and a pH of 7.347 and pCO2 of 46.8 mm Hg on venous blood sample. Thorax CT scan was performed for better evaluation of the lung parenchyma. Peribronchovascular interstitial thickness was observed in bilateral paracentral zones particularly, in lower lobes Figure1. Spiral thorax CT with 3D reconstruction was performed to show rib cage deformities obviously. Whole rib cage scanned with 3D CT (Hitachi, WSR1050, Japan. Scan parameters were 120 kV, 175 mA with a slice and collimation of 3 mm and a table speed of 5 mm/sec were used). Agenesia of the right 6th and 7th ribs, fusion of the 1st and the 2nd ribs on the left, 3rd and 4th ribs on the right hemithorax and bilateral fusion of the 8th and 9th ribs were detected [Figures 2] and Figure3.
Discussion
Spondylocostal dysostosis (SCD) has been known by various names, including Jarcho-Levin syndrome, hereditary malformations of the vertebral bodies, syndrome of bizarre vertebral anomalies, costovertebral dysplasia.[8] Since the first child with multiple vertebral segmentation defects was described in 1938 by Jarcho and Levin, less than 100 cases have been reported in the literature.[9]
Mortier et al[10] recognized 3 distinct entities based on radiographic and clinical findings: Jarcho-Levin syndrome, a lethal autosomal recessive form, characterised by a symmetric crab-chest; SCD, an autosomal dominant condition with intrinsic rib anomalies and a better prognosis; and STD, which shows considerable clinical and radiographic overlap with the latter type and greater incidence of neural tube defects. But, Cornier et al[9] recently classified clinical phenotypes into two groups: Jarcho-Levin syndrome and STD together constituted one phenotype and spondylocostal dysostosis, the other one. Typical findings of the first phenotype consist of multiple skeletal anomalies including segmentation and formation defects throughout cervical, thoracic and lumbar spine, such as hemivertebrae, block vertebrae, with fusion of the ribs at the costovertebral junction and other accompanying anomalies such as spina bifida, hernias, and imperforate anus. Typical findings of the spondylocostal dysostosis are axial skeletal malformations, but with asymmetric rib anomalies such as broadening, fusion of the ribs and other associated anomalies like congenital cardiac, urogenital diseases, anal atresia. Turnpenny[11] et al reported novel mutations in the Delta-like 3 (DLL3) gene on chromosome 19 in patients with autosomal recessive type spondylocostal dysostosis. Vertebral and costal anomalies detected in our patient and presence of respiratory distress, tethered cord, imperforate anus suggest the possibility of spondylothoracic dysostosis. The chromosomal analysis of the patient was not performed since the parents were reluctant for testing because of their religious believes.
Cornier et al[10] reported that patients with SCD had better prognosis than patients with STD due to asymmetry of the thoracic anomalies resulting in a less restrictive thorax in SCD. It is important to determine the respiratory status in these patients, since it predicts the clinical outcome. Radiographic findings on chest X-ray are difficult to interpret because of the malformed rib cage and not related to the severity of the respiratory problems[5]. CT imaging may be preferred in the evaluation of these children but there are some challenges as rapid respiratory rate, movements, small size and little internal fat to provide intrinsic contrast. Spiral CT is able to address some of these issues because of the speed of data acquisition, which helps to eliminate interscan and intrascan motion resulting in true volume data sets. The short scanning time of spiral acquisition like 32-40 seconds allows the procedure to be performed without sedation in pediatric patients. Spiral CT with 3D imaging provides exact measurement of the bony rib cage.[12]-[14] Cornier et al[10] demonstrated features of rib and vertebral anomalies in patients with STD and SCD with reconstructed 3D spiral CT. We also showed our patient's rib cage abnormalities with the same method.
Paradoxical chest movements, herniation of the lungs and diaphragm through the defect, recurrent respiratory infections lead to progressive thoracic insufficieny in children with spondylocostal dysostoses. Nichter et al[6] did the first chest wall reconstruction in an infant with SCD and reported that they could correct paradoxical chest wall motions of the infant successfully. Hosalkar et al[7] used a latissimus dorsi flap to stabilize the chest wall in a 6 months old infant with SCD recently and declared that the child had improved pulmonary function throughout 8 months after the surgery. Children with the mentioned findings above may benefit from the reconstructive surgery. Our patient's parents have not decided to a reconstructive surgical procedure yet for their child.
Reconstructive 3D spiral CT imaging may help better understanding and visualization of the infant's deformities and status and better evaluation of surgical intervention in children with chest wall anomalies by the family and the surgical team.
References
1. Taybi H. Syndromes. In Taybi H, Lachman RS, eds. Radiology of Syndromes, Metabolic Disorders and Skeletal Dysplasias . 4th edn. St Louis:Mosby, 1996: 466-467.
2. Multiple Congenital Anomalies. In Winter RM, Baraitser M, eds. A Diagnostic Compendum. London: Chapman and Hall Medical, 1991: 583.
3. Kher A, Bhat M, Ratnam KL et al. Spondylocostal dysostosis. Indian J Pediatr 1993; 60: 813-818.
4. Turnpenny PD, Thwaites RJ, Boulos FN. Evidence for variable gene expression in a large inbred kindred with autosomal recessive spondylocostal dysostosis. J Med Genet 1991; 28:27-33.
5. Dorrepaal C, Sonderen L, Hennekam RCM. A neonate with multiple segmentation defects. Pediatric Clinics Amsterdam 1999; 10:2 (http://home-2.worldline.nl/~staalman/PCA/pca10_2/pca10_2_2.html).
6. Nichter LS, Chapin SD, Wells W, Downey SE. Chest-wall reconstruction for sponylocostal dysostosis. Plast Reconstr Surg 1993; 92: 746-749.
7. Hosalkar H, Thatte MR,Yagnik MG. Chest-wall reconstruction in sponylocostal dysostosis. Rare use of latissimus dorsi flap. Plast Reconstr Surg 2002; 110: 537-540.
8. Karakurt C, Kara C, Akgün D et al. Spondylocostal dysostosis: presentation of two cases. Int Pediatr 2001; 16: 173-174.
9. Cornier AS, Ramirez N, Carlo S, Reiss A. Controversies surrounding Jarcho-Levin syndrome. Curr Opin Pediatr 2003; 15: 614-620.
10. Mortier GR, Lachman RS. Multiple vertebral segmentation defects: Analysis of 26 new patients and review of the literature. Am J Med Genet 1996; 61: 310-319.
11. Turnpenny PD, Whittock N, Duncan J et al. Novel mutations in DLL3, a somitogenesis gene encoding a ligand for the Notch signalling pathway, cause a consistent pattern of abnormal vertebral segmentation in spondylocostal dysostosis. J Med Genet 2003; 40: 333-339.
12. Padhani RG, Dixon AK. Whole body computed tomography: recent development. In Grainger AR, Allison DJ, Adam A, Dixon AK, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. Florida: W.B. Saunders Co, 2001: 81-92.
13. Richenberg JL, Hansell DM. Image processing and spiral CT of the thorax. Br J Radiol 1998; 71: 708-716.
14. Pretorius ES, Haller JA. Spiral CT with 3D reconstruction in children requiring for failure of chest wall growth after pectus excavatum surgery. Clin Imaging 1998; 22: 108-116.(Tamay Zeynep, Guler Nermi)